The surviving suspect in the Boston Marathon bombings suffered an injury to his throat and may not be able to talk, a federal official told CNN on Saturday, possibly hindering attempts by authorities to question him about a motive in the attack.

With one suspect dead, authorities believe answers to a motive and whether the brothers had help rest with Dzhokar Tsarnaev, who was captured Friday night just minutes after authorities had indicated that a massive manhunt for the suspect appeared to come up empty.

The official, who was briefed on Tsarnaev’s condition, spoke on condition of anonymity.

Tsarnaev was in “serious but stable condition” and “not yet able to communicate yet,” Massachusetts Gov. Deval Patrick told reporters during an impromptu briefing on Saturday.